Moment.js how to get week of month? (google calendar style)

Question

I am using Moment.js and it is great. The problem I have now is that I can\'t figure out how to get the week of the month a certain date is. I can only find \"week of year\"

Answer 1

I think it is a bit late to respond but I don't see the same solution as mine so I am posting.

moment().weeks() - moment().add(0, 'month').startOf('month').weeks() + 1

"moment().weeks()" returns the number of weeks for today within that year.

"moment().add(0, 'month').startOf('month').weeks()" returns the number of weeks for the first day of the month within that year.

Answer 2

Here's Robin Malfait's solution implemented with the lightweight library date-fns

import {
    differenceInDays,
    startOfMonth,
    startOfWeek,
    getDate
} from 'date-fns'

const weekOfMonth = function (date) {
    const firstDayOfMonth = startOfMonth(date)
    const firstDayOfWeek = startOfWeek(firstDayOfMonth)
    const offset = differenceInDays(firstDayOfMonth, firstDayOfWeek)
    return Math.ceil((getDate(date) + offset) / 7)
}

export default weekOfMonth

Answer 3

It seems that moment.js does not have the method that implements the functionality that you are looking for. However, you can find the nth number of a certain day of the week in a month is using the Math.ceil of the date / 7 For example:

var firstFeb2014 = moment("2014-02-01"); //saturday
var day = firstFeb2014.day(); //6 = saturday
var nthOfMoth = Math.ceil(firstFeb2014.date() / 7); //1

var eightFeb2014 = moment("2014-02-08"); //saturday, the next one
console.log( Math.ceil(eightFeb2014.date() / 7) ); //prints 2, as expected

It looks like this is the number you are looking for, as demonstrated by the following test

function test(mJsDate){
   var str = mJsDate.toLocaleString().substring(0, 3) +
             " number " + Math.ceil(mJsDate.date() / 7) +
             " of the month";
   return str;
}

for(var i = 1; i <= 31; i++) {
   var dayStr = "2014-01-"+ i;
   console.log(dayStr + " " + test(moment(dayStr)) );
}

//examples from the console:
//2014-01-8 Wed number 2 of the month
//2014-01-13 Mon number 2 of the month
//2014-01-20 Mon number 3 of the month
//2014-01-27 Mon number 4 of the month
//2014-01-29 Wed number 5 of the month

Answer 4

Simple using moment.js

function week_of_month(date) {

        prefixes = [1,2,3,4,5];

    return prefixes[0 | moment(date).date() / 7] 

}

Answer 5

I think the answer to this question will be helpful, even though it doesn't use moment.js as requested:

Get week of the month

Answer 6

function countWeekdayOccurrencesInMonth(date) {

    var m = moment(date),
            weekDay = m.day(),
            yearDay = m.dayOfYear(),
            count = 0;

    m.startOf('month');
    while (m.dayOfYear() <= yearDay) { 
        if (m.day() == weekDay) {
            count++; 
        }
        m.add('days', 1); 
    }

    return count;
}